ExcLct Measurement of Trees. 



165 



trees appeared to suflfer severely, and more so than ever- 

 green trees, but the oak tribe, so far as observed, least of 

 all. For this failure three climatic causes were assigned : — 

 a great reduction of the mean temperature of every grow- 

 ing month under the average, a similar reduction of sun- 

 shine, and the loss of the greater part of one of our usual 

 growing months iu consequence of both climatic deficiencies 

 having prevailed so seriously as to delay the development 

 of the new leaves till near the beginning of July. 



In continuation of these inquiries, I have now to state 

 the result of measurements of the same trees for the recent 

 favourable season of 1880. 



The previous autumn of 1879 was unfavourable for the 

 ripening of young w^ood. September, indeed, was not far 

 amiss ; but the month of October was ungenial. This 

 circumstance, together with the loss of June as a growing 

 mouth, was a sorry omen for the solidification of young- 

 wood, as well as for the formation of buds, and consequently 

 for their ability to resist uninjured the customary frosts of 

 winter. But it so fell out that in this unprepared condition 

 they were exposed during great part of December to an 

 asperity of climate unprecedented in this latitude, and such 

 as it may be earnestly hoped will not be soon again paralleled. 

 For nearly three weeks, in the country around Edinburgh, 

 the minimum was often a little above zero F, and sometimes 

 below it ; and in other parts of the Lowlands, especially in 

 Berwickshire and Roxburghshire, much lower temperatures 

 were noted. A descent to — 18^, and in one instance to 

 — 20° was authenticated. 



I have given this general account of the weather since 

 autumn 1879 chiefly from a diary of observations kept by 

 myself. But since drawing it up, I have been favoured 

 with the following confirmatory statement of the differ- 

 ences from the average of the previous twenty-four years in 

 the mean temperature of each month after August 1879, 

 kindly furnished by Mr Buchan : — 



